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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

25037 results found.

  1. GRB 070125: P60 Optical Afterglow Candidate
  2. GRB 070126?: Swift detection of a possible burst
  3. GRB070125 redshift request
  4. IPN localization of GRB070124 (short duration, hard spectrum)
  5. GRB 070110: Ep,i - Eiso correlation
  6. GRB 070107: Suzaku WAM observation of the prompt emission
  7. GRB070110: Swift XRT Team refined analysis
  8. GRB 070110, Swift-BAT refined analysis
  9. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  10. GRB 070110: Swift detection of a burst with a possible optical afterglow
  11. GRB 070107: Possible UVOT Afterglow
  12. GRB 070107, Swift-BAT refined analysis
  13. GRB 070107: Swift detection of a burst
  14. VLA observation of GRB 061222B
  15. VLA detection of GRB 061222A
  16. GRB070103: APO SPIcam i' and z' limits
  17. GRB070103: KPNO 4m+FLAMINGOS J limit
  18. GRB 070103: Swift/UVOT Upper limits
  19. GRB070103: Swift XRT refined analysis
  20. GRB 070103, Swift-BAT refined analysis
  21. GRB 070103: NOT observations
  22. GRB 070103: TAROT Calern observatory optical observations
  23. Retractions of previous Swift-BAT triggers
  24. erratum : SDSS Pre-burst Observations of GRB061126
  25. GRB 061210: Swift/XRT Astrometry Correction
  26. GRB 050826: MDM Redshift
  27. GRB 061222A: Confirmation of Gemini Afterglow Candidate
  28. GRB 061222A: Xinglong Optical Limit
  29. GRB 061222A: Gemini Afterglow Candidate
  30. GRB 061222B, Swift-BAT refined analysis
  31. GRB061222A Swift/UVOT: Upper Limits
  32. GRB 061222B: Swift/UVOT Upper limits
  33. GRB 061222B: Observation with the KANATA 1.5m telescope
  34. GRB 061222A: Observation with the KANATA 1.5m telescope
  35. GRB 061222B: BOOTES-IR optical observations
  36. GRB 061222B: SARA upper limit
  37. GRB 061217: Magellan host galaxy redshift
  38. GRB 061222A, Swift-BAT refined analysis
  39. GRB 061222B: REM NIR/optical observations
  40. GRB 061222B: TAROT La Silla observatory optical observations
  41. GRB 061222B: Swift detection of a burst
  42. GRB 061222b: optical afterglow
  43. GRB 061222A: Prompt ROTSE-III Optical Limits
  44. GRB 061222: Swift detection of a burst
  45. GRB 061218: TAROT La Silla observatory optical observations
  46. GRB 061217: TAROT Calern observatory optical observations
  47. GRB 061218: TORTOREM optical upper limits
  48. GRB 061218, Swift-BAT refined analysis
  49. GRB061217: VLT NIR observations
  50. GRB 061218, SMARTS optical/IR observations
  51. GRB 061218: REM prompt observations
  52. Swift triggers (#251863) on a possible burst
  53. GRB061217: Swift/UVOT refined analysis.
  54. GRB 061217: optical observations at Calar Alto
  55. GRB061217 - Swift/XRT refined analysis
  56. GRB 061217, Swift-BAT refined analysis
  57. GRB 061217: Magellan Observations
  58. GRB 061217: REM prompt observations
  59. GRB 061217: ROTSE-III Optical Limits
  60. GRB061210: Swift/UVOT observations
  61. GRB 061210: Swift XRT analysis - Possible counterparts
  62. GRB 061210: Gemini/GMOS Observations
  63. GRB 061126: Radio Observations
  64. GRB061210: Radio Observations
  65. GRB 061202: Suzaku WAM observation of the prompt emission
  66. GRB 061210, Swift-BAT refined analysis of the SHB
  67. Optical Afterglow observations of GRB 061126
  68. GRB 060926: MASTER: discovery of the optical flare
  69. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  70. GRB 061202: TORTOREM optical upper limits
  71. GRB 061201: VLT optical decay
  72. GRB 061201: SOAR Confirmation of Candidate Afterglow
  73. GRB061202: FRAM early follow-up limit
  74. GRB061202 optical limit by "Pi of the Sky"
  75. GRB061202: optical/NIR observations with REM
  76. GRB061202: Swift/UVOT Upper Limits
  77. GRB 061202, Swift-BAT refined analysis
  78. GRB 061202: Swift detection of a burst
  79. GRB 061201: VLT optical observations
  80. GRB 061201: Initial UVOT Observations
  81. GRB 061201, Swift-BAT refined analysis of the SHB
  82. GRB 061201: Swift detection of a short hard burst
  83. INT+WFC observations of GRB 061126
  84. Swift XRT on-board boresight update
  85. GRB 061126: optical observation
  86. GRB 061126: Tautenburg afterglow observations
  87. GRB061126: Optical afterglow observations from MIRO
  88. GRB061126: Optical afterglow observations from MIRO
  89. GRB 061126 : SDSS Pre-Burst Observations
  90. GRB 061126: Swift-XRT refined analysis
  91. GRB 061126: Swift/UVOT Observations
  92. GRB 061126, Swift-BAT refined analysis
  93. GRB 061126: Early Detection of the IR Afterglow
  94. GRB 061126: Swift/UVOT Afterglow Detection
  95. GRB 061122: Candidate Optical Afterglow
  96. GRB 061121: Ep,i - Eiso correlation
  97. GRB061122: Swift/UVOT Optical Observations
  98. GRB061121: P60 Observations
  99. Radio detection of GRB 061121
  100. GRB061122: Swift-XRT position

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